Charging pad with guiding contours to align an electronic device on the charging pad and efficiently transfer near-field radio-frequency energy to the electronic device

ABSTRACT

A charging pad for transmitting wireless power waves for charging an electronic device is disclosed. The charging pad includes transmitting antenna elements that are configured to be selectively activated to transmit wireless power waves to the electronic device for wireless charging. The charging pad includes a charging surface including a guiding contour that aligns a position of the electronic device on the charging surface such that a transmitting antenna element is within a predetermined distance of the electronic device and has a predetermined coupling efficiency. The charging pad further includes a transmitter controller integrated circuit (IC). The transmitter controller IC is configured to detect the position of the electronic device on the charging surface and selectively activate at least one transmitting antenna element based on a determination that the at least one transmitting antenna element is within the predetermined distance of the electronic device and has the predetermined coupling efficiency.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/120,003, filed on Dec. 11, 2020, entitled “CHARGING PAD WITH GUIDINGCONTOURS TO ALIGN AN ELECTRONIC DEVICE ON THE CHARGING PAD ANDEFFICIENTLY TRANSFER NEAR-FIELD RADIO-FREQUENCY ENERGY TO THE ELECTRONICDEVICE,” which claims priority from U.S. Provisional Application Ser.No. 62/947,947, filed Dec. 13, 2019, entitled “CHARGING PAD WITH GUIDINGCONTOURS TO ALIGN AN ELECTRONIC DEVICE. ON THE CHARGING PAD ANDEFFICIENTLY TRANSFER NEAR-FIELD RADIO-FREQUENCY ENERGY TO THE ELECTRONICDEVICE,” each of which is herein fully incorporated by reference in itsrespective entirety.

TECHNICAL FIELD

The embodiments herein generally relate to antennas and charging padsused in wireless power transmission systems and, more specifically, to acharging pad with guiding contours to align an electronic device on thecharging pad, and efficiently transfer near-field radio-frequency energyto the electronic device (e.g., transmitting elements of the pad cantransmit the near-field radio-frequency energy to receiving elementsembedded in movable arms (such as arms of smart glasses)).

BACKGROUND

Conventional charging pads utilize inductive coils to generate amagnetic field that is used to charge a device. Users typically mustplace the device at a specific position on the charging pad and areunable to move the device to different positions on the pad, withoutinterrupting or terminating the charging of the device. This results ina frustrating experience for many users as they may be unable to placethe device at the exact right position on the pad in which to startcharging and/or efficiently charge their device.

This issue is particularly problematic for electronic devices thatinclude movable arms (such as movable arms of smart glasses), as theposition of receiving elements residing or embedded in these movablearms constantly changes, making it even more difficult for users toplace such devices at the exact right position on the pad.

SUMMARY

Accordingly, there is a need for wireless charging systems (e.g., RFcharging pads) that are able to selectively activate antenna elements sothat the charging pad is capable of efficiently charging a device thatis placed at any position on the pad, and so that the charging pad isable to charge an electronic device that has movable arms that might beplaced at a number of different positions on the pad. In someembodiments, these systems and methods for charging an electronic deviceusing wirelessly transmitted radio-frequency power (RF) waves includethe electronic device (e.g., smart glasses) with one or more movablearms. At least one movable arm of the electronic device includes areceiving antenna element. The system includes a charging pad thatincludes a housing with a surface. The housing includes at least oneguiding contour on the surface configured to align placement of theelectronic device on the surface of the housing. The charging padincludes transmitting antenna elements that are selectively activated totransmit radio-frequency power waves to the receiving antenna element ofthe electronic device. Some embodiments of the charging pad may includeswitches coupled between one or more power amplifiers and thetransmitting antenna elements of the charging pad. The switches allowfor selective activation of the transmitting antenna elements based onthe placement of the electronic device and/or the receiving antennaelements that can be embedded in movable arms of the electronic device.Such systems and methods of use thereof help to eliminate userdissatisfaction with conventional charging pads, and help to enableefficient wireless charging of electronic devices that include movablearms. By selectively activating transmitting antenna elements andproviding guiding contours on the pad to ensure that the electronicdevice is aligned to enable efficient charging (discussed in more detailbelow), such systems and methods of use thereof help improve couplingefficiency and RF power transmissions by ensuring that energy transferis maximized even if movable arms of the electronic device are variouslypositioned relation to an RF charging pad, thus eliminating wastefultransmissions that may not be efficiently received.

In some embodiments, the charging pad may include splitters coupledbetween one or more power amplifiers and transmitting antenna elementsof the pad. In such embodiments, the splitters provide power from theone or more power amplifiers to at least two transmitting antennaelements of the charging pad. In this way, power may be provided todifferent zones (e.g., via the transmitting antenna elements) of thecharging pad regardless of the position of the electronic device'smovable arms relative to the charging pad. In some embodiments, thesplitters are configured as passive components and provide power to theat least two transmitting antenna elements without the use of theswitches and/or software algorithms to selectively activate transmittingantenna elements. Using the splitters as passive components can simplifythe system, without introducing additional electromagnetic interference(EMI) and electromagnetic compatibility (EMC) issues. In someembodiments, the splitters are selectively activated to provide currentand/or power to one or more switch circuits and/or transmitting antennaelements. In some embodiments, the splitters and the switches arecombined to selectively activate transmitting antenna elements, as wellas provide power to at least two transmitting antenna elementsregardless of the positions of the electronic device's movable armsrelative to the pad.

(A1) In accordance with some embodiments, a system is provided forcharging an electronic device using wirelessly transmittedradio-frequency power (RF) waves. The system includes an electronicdevice with one or more movable arms. At least one movable arm of theelectronic device includes a receiving antenna element. The systemfurther includes a charging pad that includes a housing with a surfaceand transmitting antenna elements that are each selectively activated totransmit radio-frequency power waves to the receiving antenna element ofthe electronic device. The housing of charging pad further includes atleast one guiding contour on the surface. The at least one guidingcontour aligns a position of the electronic device on the surface of thehousing. The system further includes a transmitter controller integratedcircuit (IC) configured to selectively activate particular transmittingantenna elements of the charging pad based on a determination that theparticular transmitting antenna elements satisfy matching criteria.Activating the particular transmitting antenna elements causes theparticular transmitting antenna elements to transmit the radio-frequencypower waves to the first receiving antenna element of the electronicdevice.

(A2) In accordance with some embodiments, a system is provided forcharging an electronic device using wirelessly transmittedradio-frequency power (RF) waves. The system includes an electronicdevice with one or more movable arms. At least one movable arm of theelectronic device includes a receiving antenna element. The systemfurther includes a charging pad that includes a housing with a surfaceand transmitting antenna elements that are each selectively activated totransmit radio-frequency power waves to the receiving antenna element ofthe electronic device. The housing of charging pad further includes atleast one guiding contour on the surface. The at least one guidingcontour aligns a position of the electronic device on the surface of thehousing. The system further includes a means for coupling the receivingantenna element of the electronic device to particular transmittingantenna elements of the charging pad. The means for coupling selectivelyactivates the particular transmitting antenna elements of the chargingpad based on a determination that the respective transmitting antennaelement satisfies matching criteria. Activating the particulartransmitting antenna elements of the charging pad causes the particulartransmitting antenna elements of the charging pad to transmit theradio-frequency power waves to the receiving antenna element of theelectronic device.

(A3) In accordance with some embodiments, a method of charging anelectronic device using wirelessly transmitted radio-frequency powerwaves. The method includes providing an electronic device that includingone or more movable arms. At least one movable arm includes a firstreceiving antenna element. The method further includes providing acharging pad. The charging pad includes a housing having a surface. Thehousing includes at least one guiding contour on the surface. The atleast one guiding contour is configured for aligning a position of theelectronic device on the surface of the housing. The charging pad alsoincludes two or more transmitting antenna elements that are eachselectively activated to transmit radio-frequency power waves to thefirst receiving antenna element of the electronic device. The methodfurther incudes selectively activating a respective transmitting antennaelement of the two or more transmitting antenna elements based on adetermination that the respective transmitting antenna element satisfiesmatching criteria. Activating the respective transmitting antennaelement causes the respective transmitting antenna element to transmitthe radio-frequency power waves to the first receiving antenna elementof the electronic device.

(A4) In accordance with some embodiments, a non-transitorycomputer-readable storage medium comprising executable instructions tobe executed by one or more processors that are coupled with a radiofrequency (RF) charging pad that includes one or more transmittingantenna elements. The executable instructions, when executed by one ormore processors, cause the one or more processors to, at the RF chargingpad that includes a housing having a surface, the housing including atleast one guiding contour on the surface, the at least one guidingcontour configured for aligning a position of an electronic device onthe surface of the housing; and two or more transmitting antennaelements that are each selectively activated to transmit radio-frequencypower waves to a first receiving antenna element of the electronicdevice; identify the position the electronic device on the surface ofthe housing; the electronic device including one or more movable arms;wherein at least one movable arm includes the first receiving antennaelement. The executable instructions further cause the one or moreprocessors to selectively activate a respective transmitting antennaelement of two or more transmitting antenna elements of the RF chargingpad based on a determination that the respective transmitting antennaelement satisfies matching criteria. Activating the respectivetransmitting antenna element causes the respective transmitting antennaelement to transmit the radio-frequency power waves to the firstreceiving antenna element of the electronic device.

(A5) In some embodiments of any of A1-A4, the at least one guidingcontour aligns the position of the electronic device on the surface ofthe housing such that the receiving antenna element included in the atleast one movable arm of the electronic device is a predetermineddistance from the respective transmitting antenna element of the two ormore transmitting antenna elements or has a predetermined couplingefficiency greater than 40%. The transmitter controller IC determiningthat the matching criteria are satisfied upon detecting that the atleast one movable arm of the electronic device is (i) the predetermineddistance from the respective transmitting antenna element of the two ormore transmitting antenna elements and (ii) couples with the respectivetransmitting antenna element of the two or more transmitting antennaelements at a predetermined coupling efficiency greater than 40%

(A6) In some embodiments of any of A1-A5, the predetermined distancefrom the center of the surface of the housing is less than 5 mm (e.g.,4.5 mm, 4.0 mm, 3.5 mm, or another lower, but still suitable distance)and the predetermined coupling efficiency is at least 42%.

(A7) In some embodiments of any of A1-A6, the predetermined distancefrom the center of the surface of the housing is less than 2 mm (e.g.,1.5 mm, 1.0 mm, 0.5 mm, or another lower, but still suitable distance)and the predetermined coupling efficiency is at least 60%.

(A6) In some embodiments of any of A1-A7, the predetermined distancefrom the center of the surface of the housing is less than 0.1 mm (e.g.,0.09 mm, 0.08 mm, 0.07 mm, or another suitable distance) and thepredetermined coupling efficiency is at least 70%.

(A9) In some embodiments of any of A1-A8, the electronic device includesa second movable arm of the one or more movable arms and the secondmovable arm includes another receiving antenna element.

(A10) In some embodiments of any of A1-A9, the first receiving antennaelement includes a first meandering pattern of a conductive contact thathas a first number of turns and the second receiving antenna elementincludes a second meandering pattern of a conductive contact that has asecond number of turns.

(A11) In some embodiments of any of A1-A10, the first meandering patternof the conductive contact and the second meandering pattern of theconductive contact are the same.

(A12) In some embodiments of any of A1-A11, the first meandering patternof the conductive contact and the second meandering pattern of theconductive contact are distinct.

(A13) In some embodiments of any of A1-A12, the first meandering patternof the conductive contact has a first number of turns and the secondmeandering pattern of the conductive contact has a second number ofturns.

(A14) In some embodiments of any of A1-A13, the first meandering patternof the conductive contact has a larger surface area than the secondmeandering pattern of the conductive contact.

(A15) In some embodiments of any of A1-A14, the first receiving antennaelement and the second receiving antenna element are configured toreceive the radio-frequency power waves transmitted from the respectivetransmitting antenna element.

(A16) In some embodiments of any of A1-A15, the transmitter controllerintegrated circuit selectively activates a different transmittingantenna element to provide power to the second receiving antenna basedon a determination that the different transmitting antenna elementsatisfies matching criteria.

(A17) In some embodiments of any of A1-A16, the transmitter controllerintegrated circuit selectively activates the respective transmittingantenna to provide power to the second receiving antenna based on adetermination that the respective transmitting antenna element satisfiesmatching criteria.

(A18) In some embodiments of any of A1-A17, the at least one movable armfolds into a first or second configuration. When the at least onemovable arm is folded in either the first or second configuration, thefirst receiving antenna element is coupled with the respectivetransmitting antenna element of the two or more transmitting antennaelements at the predetermined coupling efficiency.

(A19) In some embodiments of any of A1-A18, the respective and thedifferent transmitting antenna elements each include symmetricallyshaped radiators.

(A20) In some embodiments of any of A1-A19, the respective and thedifferent transmitting antenna elements each include asymmetricallyshaped radiators.

(A21) In some embodiments of any of A1-A20, the at least one guidingcontour is a border, the border lining at least one edge the housing.

(A22) In some embodiments of any of A1-A21, the at least one guidingcontour is a rise and the rise is centrally located on the surface.

(A23) In some embodiments of any of A1-A22, the at least one guidingcontour is a cradle configured to receive the electronic device.

(A24) In some embodiments of any of A1-A23, the surface is made of aradio-frequency-transparent dielectric material that is positioneddirectly above the two or more transmitting antenna elements.

(A25) In some embodiments of any of A1-A24, the transmitter controllerIC is in communication with a power splitter that is configured toprovide current from a power amplifier to respective switches eachassociated with the respective and the different transmitting antennaelements.

(A26) In some embodiments of any of A1-A25, activating at least one ofthe respective or the different transmit antennas includes sendingcontrol instructions to one or both the switches and the poweramplifier.

(A27) In some embodiments of any of A1-A26, the electronic device isselected from the group consisting of: smart watches, headphones, or,smart door handle.

(A28) In some embodiments of any of A1-A27, the first receiving antennaelement is a monopole antenna.

(A29) In some embodiments of any of A1-A28, at least one transmittingantenna element of the two or more transmitting antenna elements issymmetrical to the first receiving antenna element.

(A30) In some embodiments of any of A1-A29, the symmetry is based atleast in part on respective meandering patterns of the at least onetransmitting antenna element and the first receiving antenna element.

Thus, wireless charging systems configured in accordance with theprinciples described herein are able to charge an electronic device thathas movable arms that can be placed at any position on the RF chargingpad.

Note that the various embodiments described above can be combined withany other embodiments described herein. The features and advantagesdescribed in the specification are not all inclusive and, in particular,many additional features and advantages will be apparent to one ofordinary skill in the art in view of the drawings, specification, andclaims. Moreover, it should be noted that the language used in thespecification has been principally selected for readability andinstructional purposes, and not intended to circumscribe or limit theinventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

So that the present disclosure can be understood in greater detail, amore particular description may be had by reference to the features ofvarious embodiments, some of which are illustrated in the appendeddrawings. The appended drawings, however, merely illustrate pertinentfeatures of the present disclosure and are therefore not to beconsidered limiting, for the description may admit to other effectivefeatures.

FIG. 1 is a high-level block diagram of an RF charging pad in accordancewith some embodiments.

FIG. 2 illustrates a system for charging an electronic device on an RFcharging pad, in accordance with some embodiments.

FIG. 3 illustrates another system for charging an electronic device onan RF charging pad, in accordance with some embodiments.

FIGS. 4A and 4B illustrate RF charging pad surfaces with transmittingantenna elements in accordance with some embodiments.

FIGS. 5A and 5B illustrate receiving antenna elements in or on a movablearm of an electronic device in accordance with some embodiments.

FIGS. 6A-6C illustrate an RF charging pad with a border-guiding contourused to align an electronic device in accordance with some embodiments.

FIGS. 7A and 7B illustrate an RF charging pad with a rise-guidingcontour used to align an electronic device in accordance with someembodiments.

FIGS. 8A and 8B illustrate an RF charging pad with a mount-guidingcontour used to align an electronic device in accordance with someembodiments.

FIGS. 9A and 9B illustrate an RF charging pad with divots as guidingcontours that align an electronic device in accordance with someembodiments.

FIGS. 10A and 10B illustrate different configurations of a receivingantenna element on or in one or more movable arms of an electronicdevice in accordance with some embodiments.

FIG. 11 is a flow chart of a method of charging an electronic devicethrough radio frequency (RF) power transmission by using selectedtransmitting antennas of a RF charging pad in accordance with someembodiments.

FIGS. 12A and 12B illustrate coupling efficiency on the surface of thecharging when the movable arms of the electronic device are folded indifferent configurations in accordance with some embodiments.

FIG. 13 illustrates an electromagnetic field plot of the electronicdevice on the RF charging pad in accordance with some embodiments.

In accordance with common practice, the various features illustrated inthe drawings may not be drawn to scale. Accordingly, the dimensions ofthe various features may be arbitrarily expanded or reduced for clarity.In addition, some of the drawings may not depict all of the componentsof a given system, method or device. Finally, like reference numeralsmay be used to denote like features throughout the specification andfigures.

DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. In the following detaileddescription, numerous specific details are set forth in order to providea thorough understanding of the various described embodiments. However,it will be apparent to one of ordinary skill in the art that the variousdescribed embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components,circuits, and networks have not been described in detail so as not tounnecessarily obscure aspects of the embodiments.

FIG. 1 is a high-level block diagram of an RF wireless powertransmission system 150 in accordance with some embodiments. In someembodiments, the RF wireless power transmission system 150 includes atransmission pad 100 (also referred to herein as RF charging pad 100 orRF transmission pad 100). In some embodiments, the RF charging pad 100includes two or more transmitting antenna elements 102 that areselectively powered/fed by one or more power amplifiers (PA)s 104-1, . .. 104 n. In some embodiments, at least one transmitting (TX) antennaelement (e.g., 102-1, 102-2, 102-3, . . . 102 n) is activated by one ormore switch circuits 108-1, . . . 108 n coupled to the PAs 104 via oneor more splitters 106-1, . . . 106 n. Alternatively or additionally, insome embodiments, splitters 106 provide power from the PAs 104 to one ormore switch circuits (e.g., 108-1 . . . 108 n). In some embodiments, theRF charging pad 100 includes an RF power transmitter integrated circuit160 (also referred to herein as transmitter controller IC). In someembodiments, the RF charging pad 100 includes one or more communicationscomponents 110 (e.g., wireless communication components, such as WI-FIor BLUETOOTH radios), discussed in more detail below. In someembodiments, the RF charging pad 100 includes a power input configuredto be electrically coupled to a power source.

As discussed below, there are a number of different embodiments used toconvey current from the PAs 104 to the TX antenna elements 102. In afirst embodiment, each individual PA 104 is coupled with a splitter 106(e.g., PA 104-1 is coupled with splitter 106-1), which allows forconveying current from a single PA to multiple different TX antennaelements 102. In a second embodiment, each PA 104 is coupled with asplitter 106 and with a switch 108, so that individual TX antennaelements 102 can individually be activated to transmit wireless powerwhile reducing the number of PAs 104 needed (e.g., a switch to one ofthe TX antenna elements can be opened or sent to ground to ensure thatno current is provided to that TX antenna element, even though a same PA104 is being used to convey current to another TX antenna element alongthe same splitter 106). In a third embodiment, each PA 104 is coupledwith a switch 108, so that individual TX antenna elements 102 canindividually be activated to transmit wireless power conveyed by adedicated PA 104. (e.g., a switch to one of the TX antenna elements canbe opened or sent to ground to ensure that no current is provided tothat TX antenna element, each TX antenna element 102 coupled to adedicated PA 104).

In the first embodiment, the RF charging pad 100 includes one or moresplitters 106 without one or more switch circuits 108. The one or moresplitters 106 are coupled between the one or more PAs 104 and the TXantenna elements 102. In some embodiments, the splitters provide currentfrom the one or more PAs to at least two TX antenna elements of thecharging pad 100. In some embodiments, the one or more splitters 106equally distribute the current from the one or more PAs 104 to the TXantenna elements 102. For example, a splitter 106 coupled between the aPA 104 and at least two TX antenna elements 102 provides current to theat least two TX antenna elements 102. In some embodiments, the one ormore splitters 106 are configured as passive components that do not usesoftware and/or algorithms to provide current to the at least two TXantenna elements 102. Using the one or more splitters 106 as passivecomponents simplifies the system and removes additional Electromagneticinterference (EMI) and electromagnetic compatibility (EMC) issues.However, using the one or more splitters 106 as passive components doesnot allow for selective activation of the at least two TX antennaelements 102 or zone (e.g., current is split among the at least two TXantenna elements 102 without a switching mechanism to provide and/orremove the current from TX antenna elements 102).

Additionally or alternatively, the first embodiment includes one or moresplitters 106 that are not passive components (e.g., use software and/oralgorithms to provide current to the at least two TX antenna elements102). In some embodiments, the one or more splitters 106 arecommunication with the transmitter controller IC 160 and are used toselectively provide and/or remove (e.g., divert) current from the one ormore PAs 104 to one or more TX antenna elements 102 or zones of thecharging pad. In some embodiments, the transmitter controller IC 160 isconfigured to send control instructions to the one or more splitters 106to selectively provide and/or remove (e.g., divert) current from the oneor more PAs 104 to the one or more TX antenna elements 102 or zones ofthe charging pad. The transmitter controller IC 160 is configured toselectively provide current to the one or more TX antenna elements 102based on satisfaction of matching criteria as discussed below. In someembodiments, the one or more splitters 106 selectively provide currentfrom the one or more PAs 104 to reduce the number of active or used PAs104 and/or remove the current from one or more TX antenna elements 102(e.g., to dedicate a PA to a TX antenna element 102 or to preventcurrent from being provided to one or more TX antenna elements 102). Thenon-passive one or more splitters 106 equally distribute the currentfrom the one or more PAs 104 to the one or more TX antenna elements 102(e.g. depending on the selectively activated TX antenna elements).

In the second embodiment, the RF charging pad 100 includes the one ormore splitters 106 coupled between the one or more PAs 104 and one ormore switch circuits 108. In some embodiments, the one or more splitters106 and/or the one or more switch circuits 108 are in communication withthe transmitter controller IC 160. The one or more splitters 106 areconfigured to provide current from the one or more PAs 104 to switchcircuits 108 associated with the one or more TX antenna elements 102 asdescribed in the first embodiment. In other words, the one or moresplitters 106 may be used as passive and/or non-passive components andprovide current from the one or more PAs 104 to the one or more switchcircuits 108 and/or TX antenna elements 102 as described above.

For example, a charging pad 100 may include a single PA 104 and one ormore splitters 106 that are used to provide current to multiple switchcircuits 108 and/or TX antenna elements 102 associated with the one ormore TX antenna elements 102 or zones of the RF charging pad 100. Theone or more splitters 106 may be passive components that provide thecurrent to switch circuits 108 that are used to selectively activate TXantenna elements 102 (e.g., via control instructions sent by thetransmitter controller IC 160 to the one or more switch circuits 108and/or one or more PAs 104, as described below in the third embodiment).In this way, the RF charging pad 100 prioritizes one or more TX antennaelements 102 and/or avoids providing current to a TX antenna elements102. Additionally or alternatively, the one or more splitters 106 may benon-passive components that selectively provide current or one or moreswitch circuits 108 and/or TX antenna elements 102 as described above inthe first embodiment (e.g., control instructions sent by the transmittercontroller IC 160 to the one or more splitters 106).

In this way, the charging pad 100, via transmitter controller IC 160,provides and/or removes power to one or more TX antenna elements 102 orzones, reduces the number of active or used PAs 104, dedicates one ormore PAs 104 to one or more TX antenna elements 102 or zones, and/orallows for improved distribution (e.g., improved coupling efficiency) ofusable power by selecting one or more TX antenna elements 102 or zones.Using one or more PA 104 with splitters 106 along with the switchingmechanism(s) (e.g., switch circuits 108) to activate one or more TXantenna elements 102 and/or zones provide coverage over the entire RFcharging pad 100 area (e.g. surface area discussed in FIG. 2).

In the third embodiment, the RF charging pad 100 includes one or moreswitch circuits 108 without one or more splitters 106. The one or moreswitch circuits 108 are coupled between the one or more PAs 104 and theTX antenna elements 102. Additionally, the one or more switch circuits108 are in communication with the transmitter controller IC 160. The RFcharging pad 100, via transmitter controller IC 160, operates the one ormore switch circuits 108 to selectively activate the TX antenna elements102 (e.g., by providing power from one or more PAs 104 to theselectively activated the TX antenna elements 102). In some embodiments,RF power is controlled and modulated at the RF charging pad 100 viaswitch circuits 108 as to enable the RF wireless power transmissionsystem 150 to send RF power to one or more wireless receiving devicesvia the TX antenna elements 102. In some embodiments, the transmittercontroller IC 160 is configured to selectively activate one or more TXantenna elements 102 based on satisfaction of matching criteria asdiscussed below. Activating the one or more TX antenna elements 102includes sending control instructions to one or more switch circuits 108and/or one or more PAs 104. In some embodiments, activating the one ormore TX antenna element 102 causes the transmission the one or more RFpower waves from the one or more TX antenna elements.

In each of these described embodiments, a single PA 104 may be used toprovide power to the selectively activated the TX antenna elements 102.For example, a single PA 104 can be used with one or more splitters 106to provide power to TX antenna elements 102, one or more switch circuits108 to provide power to TX antenna elements 102, and/or any combinationthereof. Using a single PA with one or more splitters 106 and/or one ormore switch circuits 108 allows the RF charging pad 100 to efficientlytransfer energy to the electronic device 202 as discussed below.Further, the use of a single PA 104 has the added advantage of reducingthe cost of the RF charging pad 100 that results in a better price pointfor users.

In some embodiments, the optional communication component(s) 110 enablecommunication between the RF charging pad 100 and one or morecommunication networks. In some embodiments, the communicationcomponent(s) 110 are capable of data communications using any of avariety of custom or standard wireless protocols (e.g., IEEE 802.15.4,Wi-Fi, ZigBee, 6LoWPAN, Thread, Z-Wave, Bluetooth Smart, ISA100.11a,WirelessHART, MiWi, etc.) custom or standard wired protocols (e.g.,Ethernet, HomePlug, etc.), and/or any other suitable communicationprotocol, including communication protocols not yet developed as of thefiling date of this document.

In some instances, the communication component(s) 110 are not able tocommunicate with wireless power receivers for various reasons, e.g.,because there is no power available for the communication component(s)to use for the transmission of data signals or because the wirelesspower receiver itself does not actually include any communicationcomponent of its own. As such, it is important to design near-fieldcharging pads that are still able to uniquely identify different typesof devices and, when a wireless power receiver is detected, determine ifthat wireless power receiver is authorized to receive wireless power.For instance, the embodiments described herein can be used inconjunction with the signature-signal-generating and -receiving circuitsdescribed in commonly-owned U.S. patent application Ser. Nos. 16/024,640and 16/045,637, which are hereby incorporated by reference for allpurposes. In particular, reflected power can be collected and analyzedto identify signature signals and to thereby determine whether anauthorized device is present and/or also whether an object other than awireless power receiver is present as explained in FIGS. 3A-3H and 9A-9Bof commonly-owned U.S. patent application Ser. Nos. 16/024,640 and16/045,637.

FIG. 2 illustrates a system for charging an electronic device inaccordance with some embodiments. In some embodiments, system 200includes RF charging pad 100 and electronic device 202. In someembodiments, RF charging pad 100 includes at least two TX antennaelements 102. In some embodiments, the at least two TX antenna elements102 are a same type of antenna (e.g., a meandering line antenna with aconductive line that has a number of turns). In some embodiments, the atleast two TX antenna elements 102 are symmetrically-shaped. For example,as illustrated in FIG. 2, the at least two TX antenna elements 102 aresymmetrically-shaped along the x and y axes.

In other embodiments, the at least two TX antenna elements 102 can beasymmetrically-shaped, e.g., by having different numbers of turns alongthe respective TX antenna elements, by having a different length foreach of the respective TX antenna elements, by having different sectionlengths after each of the turns, by having different heights (along they-axis), etc. In some of these other embodiments, the at least two TXantenna elements 102 can be asymmetrically-shaped, while two othertransmitter antenna elements 102 can still be symmetrically-shaped, suchthat the charging pad 100 includes pairs of TX antenna elements 102 thatare symmetrically- and asymmetrically-shaped.

In some embodiments, the at least two TX antenna elements 102 are in ameandering pattern of a conductive contact/line (e.g., winding, snakingand/or curving pattern of a metallic wire, which is an example of theconductive contact/line). For instance, each of the at least two TXantenna elements 102 are in a winding pattern and include an n-number ofturns from the starting point.

In some embodiments, the RF charging pad 100 includes a housing 204. Insome embodiments, the housing 204 has a surface 206 that includes atleast one guiding contour 208. In some embodiments, the at least oneguiding contour 208 (e.g., depicted in FIG. 2 as a raised edge along aperimeter of the charging pad 100) is configured to align a position ofthe electronic device 202 on the surface 206 of the housing 204. In someembodiments, the guiding contour 208 is configured to align one or moreof (i) a body portion of the electronic device 202 (e.g., a frameportion of the smart glasses 202), and (ii) movable arms of the elementdevice 202 when those movable arms are in their respective fully foldedpositions (e.g., fully folded such that the movable arms are folded sothat they contact the body portion of the electronic device, or contactthe other movable arm after it has contacted the body portion of theelectronic device). In some embodiments, the at least one guidingcontour 208 aligns the position of the electronic device (e.g., bodyportion and/or movable arms in their fully folded positions) on thesurface of the RF charging pad 100 to satisfy the matching criteria (asdiscussed below) and enable the transfer of energy and/or to improve theefficiency of the energy transferred. In some embodiments, the surface206 is made of a radio-frequency-transparent dielectric material that ispositioned directly above the at least two or more TX antenna elements102. In some embodiments, the antennas operate in frequency bands ofgenerally 900 MHz, 2.4 GHz, or 5.7 GHz bands.

In some embodiments, electronic device 202 includes one or more movablearms 210-1, . . . 210 n. In some embodiments, the one or more movablearms 210 are coupled to the electronic device 202. In some embodiments,the electronic device 202 is a pair of glasses (e.g., eyeglasses,sunglasses, etc.), a smart watch, headphones, smart door and/or handle,and/or other powered devices that include movable arms (e.g., varioustoys including remote control helicopters with movable arms in the formof rotor blades). For instance, as illustrated in FIG. 2, electronicdevice 202 is a pair of glasses. In some embodiments, the one or moremovable arms 210 include a receiving (RX) antenna element 212. Forinstance, in some embodiments, an electronic device 202 can have morethan one movable arm and a single RX antenna element 212. In someembodiments, the receiving antenna is internally and/or externallyconnected to the one or more movable arms 210. In some embodiments, eachmovable arm of the one or more movable arms 210 includes a RX antennaelement 212. In some embodiments, the RX antenna element 212 of the oneor more movable arms 210 is configured to receive transmitted RF powerwaves from the at least two TX antenna elements 102. In someembodiments, the RX antenna element 212 of the one or more movable arms210 uses the energy transferred from the at least two TX antennaelements 102 of the RF charging pad 100 to charge a battery and/or todirectly power the electronic device 202. In some embodiments, theantennas operate in frequency bands of generally 900 MHz, 2.4 GHz, or5.7 GHz bands. RX antenna elements 212 are discussed in further detainin FIGS. 5A and 5B.

In some embodiments, the RX antenna element 212 is connected at anylocation and/or portion of the one or more movable arms 210. Forexample, as illustrated in FIG. 2, the RX antenna element 212 is locatedon the top of the movable arms 210 and along the length (e.g., on thez-axis and along the y-axis, as shown). In some embodiments, the RXantenna element 212 is located at an end, at the center, on the top,bottom, the inside, and/or the outside of the one or movable arms 210.In some embodiments, RX antenna elements 212 placed in each movable armof the one or more movable arms 210 are placed at the same location. Forexample, as shown in FIG. 2, RX antenna elements 212 are each located atan end of the one or more movable arms 210. In other embodiments, RXantenna elements 212 placed in each movable arm of the one or moremovable arms 210 are placed at different locations.

In some embodiments the RX antenna element 212 couples to a respectivetransmitting element of the two or more TX antenna elements (e.g., TXantenna elements 102) to transfer energy from the RF charging pad 100 tothe electronic device 202. In some embodiments, the respectivetransmitting element is selected by the RF charging pad 100 (viatransmitter controller IC 160). In some embodiments, the transmittercontroller IC 160 is configured to selectively activate a respective TXantenna element of the two or more TX antenna elements (e.g., TX antennaelement 102 is activated when the transmitter controller IC 160instructs that current should be provided to the respective TX antennaelement, e.g., by providing an instruction to one or more of a PA 104, asplitter 106, and/or a switch 108) based on a determination that therespective TX antenna element satisfies matching criteria (e.g., with aRX antenna element 212). In some embodiments, the matching criteria aresatisfied when the transmitter controller IC 160 determines that the RXantenna element 212 is within a predetermined distance from therespective TX antenna element (which can be a TX antenna element 102that is closest to a RX antenna element 212) of the two or more TXantenna elements 102. For example, in some embodiments, the respectiveTX antenna element 102 is the TX antenna element that has the leastdistance between the RX antenna element 212. Additionally oralternatively, in some embodiments, the transmitter controller IC 160determines that the matching criteria are satisfied upon detecting thatthe RX antenna element 212 in the at least one movable arm of theelectronic device couples with the respective TX antenna element of thetwo or more TX antenna elements 102 at a predetermined couplingefficiency greater than 40%.

In some embodiments, distance between the RX antenna element 212 and therespective TX antenna element 102 and/or the location of the RX antennaelement 212 is determined by the transmitter controller IC 160 based onthe power received by the RX antenna element 212. Alternatively and/oradditionally, in some embodiments, satisfaction of the matching criteriais determined by information (e.g., location, charge, etc.) received viawireless communication components 110 of the RF charging pad 100 (e.g.,electronic device 202 may provide information via WIFI, BLUETOOTH,and/or other wireless data connections). For example, in someembodiments, the RF charging pad 100 and the electronic device 202exchange messages via wireless communication, and these messages mayindicate location information that is used to select the respective TXantenna element 102. In some embodiments, the transmitter controller IC160 detects that no RX antenna element 212 is close/nearby andthereafter provides appropriate instructions (e.g., to one or more ofthe PA 104, splitter 106, and switch 108) to cease providing current tothe TX antenna element 102.

In some embodiments, the transmitter controller IC 160 is configured toselectively activate more than one TX antenna element of the two or moreTX antenna elements 102. In some embodiments, the transmitter controllerIC 160 selectively activates different TX antenna elements (e.g.,variations as discussed above). In some embodiments, the transmittercontroller IC 160 is configured to selectively activate respective TXantenna elements of the two or more TX antenna elements 102 for multipleRX antenna elements 212 of an electronic device 202. Additionally and/oralternatively, in some embodiments, the transmitter controller IC 160 isconfigured to selectively activate respective TX antenna elements of thetwo or more TX antenna elements 102 for multiple electronic devices 202that include a RX antenna elements 212. For example, the RF charging pad100 may provide usable energy to multiple electronic devices, such asmultiple pairs of smart glasses, simultaneously.

In some embodiments, the transmitter controller IC 160 detects and/oridentifies one or more transmission zones (e.g., each respective TXantenna element 102 is associated with a zone of the pad 204 that isabove the respective TX antenna element, such that, for the exampledepicted in FIG. 2, each respective TX antenna element 102 would beassociated with approximately one-quarter of a surface area of the pad204) that are closest/nearest to a RX antenna element 212 based on thepower received by the RX antenna element 212. Alternatively and/oradditionally, in some embodiments, the RF charging pad 100 receives (viawireless communication components 110) information (e.g., location,charge, etc.) from the electronic device 202. For example, in someembodiments, the transmitter and the receiver exchange messages viawireless communication, and these messages may indicate locationinformation that is used to select the respective transmitting antenna102. In some embodiments, the transmitter controller IC 160 detectsand/or identifies one or more transmission zones that areclosest/nearest to a RX antenna element 212 based on the informationreceived from the electronic device 202.

In some embodiments, the at least one guiding contour 208 aligns theposition of the electronic device 202 (e.g., (i) a body portion of theelectronic device 202 and/or (ii) movable arms of the element device 202when those movable arms are (in their respective fully folded positions)on the surface 206 of the housing 204 such that a RX antenna element 212included in the at least one movable arm 210 of the electronic device202 satisfies the matching criteria. In some embodiments, at least oneguiding contour 208 aligns the electronic device 202 such that the RXantenna element 212 is a predetermined distance from at least one TXantenna element of the two or more TX antenna elements 102. In someembodiments, the at least one guiding contour 208 aligns the electronicdevice 202 such that the RX antenna element 212 is within at least onezone of the RF charging pad 100 that includes at least one TX antennaelement of the two or more TX antenna elements 102. Additionally oralternatively, in some embodiments, the at least one guiding contour 208aligns the electronic device 202 such that the RX antenna element 212included in the at least one movable arm of the electronic device 202couples with at least one TX antenna element of the two or more TXantenna elements 102 with a predetermined coupling efficiency greaterthan 40%. In some embodiments, the at least one guiding contour 208keeps and/or stabilizes electronic device 202 on the surface 206 of thehousing 204. In some embodiments, the at least one guiding contour 208aligns the electronic device 202 (e.g., one or more of (i) a bodyportion of the electronic device 202, and (ii) movable arms of theelement device 202 when those movable arms are (in their respectivefully folded positions)) in the center of the surface 206 of the housing204 so that the matching criteria are satisfied (e.g., the RX antennaelement 212 is a predetermined distance from at least one TX antennaelement of the two or more TX antenna elements 102 and/or has a couplingefficiency greater than 40% with the at least one TX antenna element, asdetermined by the transmitter controller IC 160).

In some embodiments, a RX antenna element 212 couples with a respectiveTX antenna element of the two or more TX antenna elements 102 (e.g., TXantenna element 102 satisfying matching criteria) at a couplingefficiency greater than 40%, as measured and monitored by thetransmitter controller IC 160. In some embodiments, the couplingefficiency is at least 70%, as measured and monitored by the transmittercontroller IC 160, when the distance from the RX antenna element 212 anda TX antenna element of the two or more TX antenna elements 102 is lessthan 0.1 mm. In some embodiments, the coupling efficiency is at least60%, as measured and monitored by the transmitter controller IC 160,when the distance from the RX antenna element 212 and a TX antennaelement of the two or more TX antenna elements 102 is less than 2 mm. Insome embodiments, the coupling efficiency is at least 42%, as measuredand monitored by the transmitter controller IC 160, when the distancefrom the RX antenna element 212 and a TX antenna element of the two ormore TX antenna elements 102 is less than 5 mm. In some embodiments,when the distance from the RX antenna element 212 and a TX antennaelement of the two or more TX antenna elements 102 is greater than 5 mmthe coupling efficiency varies from 40-50%, as measured and monitored bythe transmitter controller IC 160.

In some embodiments, at least one TX antenna element of the two or moreTX antenna elements 102 is symmetrical to a RX antenna element 212. Insome embodiments, the symmetry is based at least in part on respectivemeandering patterns of the at least one TX antenna element 102 and theRX antenna element 212. For example, the at least one TX antenna element102 and the RX antenna element 212 may have symmetrically-shapedmeandering line patterns of conductive traces on both transmit andreceive sides.

FIG. 3 illustrates a system for charging an electronic device on and/ornear an RF charging pad in accordance with some embodiments. In someembodiments, system 300 includes RF charging pad 100 and electronicdevice 202 as described above in FIG. 2. For instance, in someembodiments, RF charging pad 100 includes a housing 204 with a surface206 and at least one guiding contour 208 (e.g., impression and/or divotdiscussed in more detail below). The RF charging pad 100 includes two ormore TX antenna elements (e.g., TX antenna elements 102; not shown)directly beneath the surface 206 of the RF charging pad 100. In someembodiments, electronic device 202 includes one or more movable arms210-1, . . . 210 n. The one or more movable arms 210-1, . . . 210 n eachinclude at least one RX antenna element 212.

In some embodiments, the RX antenna elements 212 of each movable arm 210is configured to receive the radio-frequency power waves transmittedfrom the RF charging pad 100. In some embodiments, the RX antennaelements 212 of each movable arm 210 couples with the same TX antennaelement(s) 102 and/or zone(s) as determined by the transmittercontroller IC 160 (as described above). In some embodiments, the RXantenna elements 212 of each movable arm 210 couples with differentrespective TX antenna elements 102 and/or different zones as determinedby the transmitter controller IC 160. For example, the respective TXantenna elements and/or zones are different transmitting antennas 102and/or zones for the receiving antenna 212 of each movable arm 210. Insome embodiments, that the different TX antenna element 102 aredetermined by the transmitter controller IC 160 (as described above). Insome embodiments, radio-frequency power waves are transmitted to the RXantenna elements 212 of each movable arm 210 simultaneously.

In some embodiments, the one or more movable arms 210 are placed indifferent configurations. In some embodiments, the differentconfigurations include folding a first movable arm followed by folding asecond movable arm and vice versa. For example, as illustrated in FIG.3, the one or more movable arms 210 fold inwardly and/or outwardly (e.g.around rotation 302) with movable arm 210-1 folded first followed bymovable arm 210 n. In some embodiments, the RF charging pad 100 providesan acceptable coupling efficiency for wireless charging (e.g., at least40%, up to at least 70%) regardless of the different foldingconfigurations. In some embodiments, the RF charging pad 100 selectivelyactivates (e.g., via the transmitter controller IC 160 as describedabove) distinct respective TX antenna elements 102 based on theconfiguration of the one or more movable arms 210 (e.g., left arm foldedbefore the right arm and vice versa).

FIG. 3 further illustrates the transmission of RF power from the RFcharging pad 100 to the electronic device 202 irrespective of theposition and/or orientation of electronic device 202 and/orconfiguration of the one or more movable arms 210. In some embodiments,electronic device 202 is improperly placed on the RF charging pad 100and/or fails to properly fit in the at least on guiding contour 208 ofthe surface 206. For example, as illustrated in FIG. 3, the electronicdevice 202 is upside down and/or may not be properly received by the atleast on guiding contour 208 of the surface 206 (e.g., electronic device202 will not be flush with the surface 206 within the guiding contours208 of the housing 204). In some embodiments, the RF charging pad 100takes into account the position and/or location of RX antenna element212 and selectively activates (via transmitter controller IC 160) arespective TX antenna element of the two or more TX antenna elements 102to efficiently transfer energy to the electronic device 202 (via RXantenna element 212), even while the device 202 is in an improperposition. In some embodiments, a user of the device 202 or charging pad100 can be notified of the improper placement of the device 202, e.g.,by flashing an LED on a surface of the pad 100, by providing audiblefeedback generated by the pad 100, by sending an electronic message tothe user, etc., which will instruct the user to properly place thedevice 202 within the guiding contours 208.

FIG. 4A illustrates a surface of the housing of the RF charging pad inaccordance with some embodiments. In some embodiments, surface 206 ofhousing 204 is made of a radio-frequency-transparent dielectric material402 that is positioned directly above the at least two or more TXantenna elements 102. In some embodiments, the dielectric material 402is a thermoplastic or thermosetting polymer. In some embodiments, thedielectric material 402 is porcelain and/or ceramic, mica, glass,plastics, air, vacuums, oxides of various metals, gasses, and/orliquids. Additionally, FIG. 4A shows the at least two or more TX antennaelements 102 symmetrically positioned in RF charging pad 100. Forexample, as illustrated in FIG. 4A, the at least two or more TX antennaelements 102 are symmetric along the x and/or the y axes. In someembodiments, the at least two or more TX antenna elements 102 of FIG. 4Aare configured as described above in FIGS. 1-3.

FIG. 4B illustrates another embodiment of the surface of the housing ofthe RF charging pad. The surface 206 of housing 204 shown in FIG. 4Bincludes the features discussed above with respect to FIGS. 1-4A. Insome embodiments, the at least two or more TX antenna elements 102 areasymmetrically positioned in RF charging pad 100. For example, asillustrated in FIG. 4B, the at least two or more TX antenna elements 102are asymmetric along the x and/or the y axes. In some embodiments, eachTX antenna element of the at least two or more TX antenna elements 102is a symmetrically shaped radiator. In other embodiments, each TXantenna element of the at least two or more TX antenna elements 102 isan asymmetrically shaped radiator. In some embodiments, theconfigurations of the at least two or more TX antenna elements 102described herein form plane inverted F antenna (PIFA).

FIGS. 5A and 5B illustrate different views of an example RX antennaelement of the one or more movable arms in accordance with someembodiments. In some embodiments, the RX antenna element 212 is amonopole antenna. In some embodiments, the RX antenna element 212 isinternally and/or externally connected to one or more movable arms 210,as was discussed above. In some embodiments, the RX antenna element 212extends a predetermined length of a movable arm 210-1 (e.g., a quarter,a third, half, three quarters, and/or the entire length of the movablearm). In some embodiments, the RX antenna element 212 includes aconductive line/contact (e.g., a metal wire or trace) that forms ameandered line pattern. For instance, the RX antenna element 212 has ameandering pattern of a conductive contact (e.g., curving, snaking,and/or winding pattern). In some embodiments, the meandering linepattern includes an n-number of turns. In some embodiments, themeandering line pattern has a uniform surface area across itspredetermined length. Alternatively and/or additionally, in someembodiments, the meandering pattern of the conductive contact has avariable surface area across its predetermined length. For example, insome embodiments, the meandering pattern of the conductive contact has asurface area that is smaller at a first end and greater at the secondend of the conductive line.

In some embodiments, a RX antenna element 212 is placed in each movablearm of the one or more movable arms 210. In some embodiments, eachadditional RX antenna element 212 is the same (e.g., same pattern,length, surface area, turns, etc.). For example, in some embodiments, afirst RX antenna element 212 and an additional RX antenna element 212are the same. in other embodiments, each additional RX antenna element212 is distinct (e.g., different number of turns for the meanderingline, patter, predetermined length, surface area, and/or othervariations between RX antenna elements 212). For example, the first RXantenna element 212 may have a length that is longer and/or shorter thanthe additional RX antenna element 212; the meandering pattern of thefirst RX antenna element 212 may include a greater and/or smaller numberof turns than the meandering pattern of the additional RX antennaelement 212; the surface area of the meandering pattern of the first RXantenna element 212 may be greater and/or smaller than the surface areaof the meandering pattern of the additional RX antenna element 212; thesurface area of the meandering pattern of the first RX antenna element212 may be uniform and the surface area of the meandering pattern of theadditional RX antenna element 212 may vary across its length; and/or anyvariation thereof.

FIGS. 6A-6C show RF charging pad 100 with a border guiding contour inaccordance with some embodiments. In some embodiments, the RF chargingpad 100 includes a housing 204 with a surface 206. In some embodiments,the surface 206 has at least one guiding contour (e.g., border 602 asdescribed below) that is configured to align a position of theelectronic device 202 on the surface 206 of the housing 204. In someembodiments, the at least one guiding contour is a border 602. In someembodiments, the border 602 lines extends along a perimeter of thehousing 204. For example, as shown in FIG. 6A, border 602 is on surface206 and runs along the edges of the housing 204. Although FIG. 6Aillustrates border 602 running along all of the edges of the housing204, border 602 may run along less than all of the edges of the housing204. Alternatively or additionally, in some embodiments, the at leastone guiding contour includes a TX antenna element 102 (e.g., a TXantenna element 102 within border 602 or directly beneath border 602).In this way, RX antenna elements 212 of the one or more moveable arms ofthe electronic device 202 placed on and/or near the at least one guidingcontour are able to couple a TX antenna element 102 included in the atleast one guiding contour.

FIG. 6B illustrates the border contour for adjusting a position ofelectronic device on the RF charging pad in accordance with someembodiments. In some embodiments, the electronic device 202 is placed onthe RF charging pad 100 at odd angles and/or different positions and theborder contour 602 adjusts the position of electronic device 202 on theRF charging pad 100 to enable the transfer of energy and/or to improvethe efficiency of the energy transferred. The electronic device 202 isnot required to be perfectly centered and/or placed at set positions ofthe RF charging pad 100 to enable the transfer of energy. For example,as illustrated in FIG. 6B, border 602 is configured to allow theelectronic device 202 to rotate and/or shift (e.g., rotation indicators604), within the boundaries of border contour 602, while placed the RFcharging pad 100. In some embodiments, border contour 602 is configuredto keep the electronic device 202 on the surface 206 of the RF chargingpad 100 (e.g., preventing electronic device 202 from falling off the ofthe RF charging pad 100, and also reminding a user to fold in both ofthe movable arms to ensure that the device 202 fits within theboundaries of border contour 602).

In some embodiments, border contour 602 is configured to enableelectronic device 202 to move a predetermined amount while maintaining adesired coupling efficiency between the at least two TX antenna elements102 of the RF charging pad 100 and the RX antenna element 212 of the oneor more movable arms 210 of the electronic device 202. For example,border contour 602 allows for the electronic device 202 to rotate and/orshift on the RF charging pad 100 left or right at least 30 degrees(e.g., from one edge of the border 602 to an opposite edge of the border602). Additionally and/or alternatively, in some embodiments, theelectronic device 202 can be rotated 180 degrees from the position shownin FIG. 6B (e.g., electronic device 202 rotated 180 degrees to the left,right, and/or flipped by a 180 degrees). It should be noted that theelectronic device 202 can be placed on and/or near the RF charging pad100 in a number of distinct orientations, such as upright, upside down,the one or more movable arms folded and/or collapsed in differentorientations and/or order, etc.

In some embodiments, the transmitter controller IC 160 is configured toselectively activate a TX antenna element of the two or more TX antennaelements 102 based on a determination that the TX antenna elementsatisfies matching criteria as discussed above in FIGS. 2 and 3.

FIG. 6C provides another depiction of placement of an electronic deviceon a charging pad with the border contour in accordance with someembodiments. As illustrated, even when the electronic device 202 isplaced imperfectly on the charging pad (e.g., such that a portion of thedevice 202 is on top of a part of the border contour 602), the pad 100can still provide wirelessly-delivered power to the device 202. Asdiscussed above, the pad 100 can also be configured to notify the userof the improper placement of the device 202.

FIGS. 7A and 7B illustrate another embodiment of the at least oneguiding contour of a surface of the RF charging pad. In someembodiments, the at least one guiding contour of the surface 206 is arise 702. In some embodiments, the rise 702 is centrally located on thesurface 206 and extends a predetermined height (e.g., 0.5 inches to 2.0inches) from the surface 206 (e.g., along the shown z-axis). In someembodiments, the rise 702 extends along the longest length of thesurface 206 (e.g., along the shown x-axis). In some embodiments, therise 702 is configured to receive electronic device 202 and align aposition of the electronic device 202 on the surface 206 of the housing204. As mentioned above, the at least one guiding contour may include aTX antenna element 102. For example, a TX antenna element 102 may tracethe exterior area and/or the circumference of the rise 702.

In some embodiments, the rise 702 enables the RF charging pad 100 totransfer energy and/or to improve the efficiency of the energytransferred to the electronic device 202. Rise 702 provides a visibleand physical contour (e.g., rise 702) for placement of the electronicdevice 202 on surface 206. In this way, rise 702 provides a user with anindication of a secure position (e.g., unlikely to fall).

FIG. 7B illustrates the rise contour of an RF charging pad, around whichan electronic device has been placed. As depicted, the rise 702 holdsand/or keeps electronic device 202 on the surface 206 of the RF chargingpad 100. In some embodiments, rise 702 allows for the electronic device202 to rotate and/or shift (e.g., rotation arrows 704) on the RFcharging pad 100 to the left or right a predetermined amount (e.g. 45degrees or less in either direction). For example, in some embodiments,the rise 702 is large enough to prevent the electronic device 202 fromhaving the one or more movable arms 210 floating and/or hanging off thesurface 206 of charging pad 100. The rise 702 enables the electronicdevice 202 to move a predetermined amount while maintaining optimalconnectivity between the at least two TX antenna elements 102 of the RFcharging pad 100 and the RX antenna element 212 of the one or moremovable arms 210 of the electronic device 202.

FIG. 7B also shows an embodiment of the electronic device 202 where a RXantenna element 212 has been placed on and/or in a side of movable arm210 (e.g., RX antenna element 212 located in the interior of movable arm210).

FIGS. 8A and 8B illustrates another embodiment of the at least oneguiding contour on a surface of the RF charging pad. As shown, the atleast one guiding contour of the surface 206 can be a mount and/orcradle 802. In some embodiments, mount 802 is configured to receive theelectronic device 202 and position the electronic device 202 over thecenter of the surface 206 of the housing 204. In some embodiments, themount 802 holds the electronic device 202 such that the one or moremovable arms 210 of the electronic device 202 make contact with thesurface 206 of the RF charging pad 100. Alternatively and/oradditionally, in some embodiments, the mount 802 holds the electronicdevice over the surface 206 of the RF charging pad 100 without makingcontact with the surface 206. In some embodiments, the mount 802 isconfigured to position electronic device 202 and/or RX antenna element212 in an optimal position with respect to the two or more TX antennaelements 102 (e.g., to produce a highest coupling efficiency). In thisway, mount 802 enables the RF charging pad 100 to transfer energy and/orto improve the efficiency of the energy transferred to the electronicdevice 202 with minimal effort required by a user. Additionally, mount802 provides a visible and/or physical contour to guide the placement ofthe electronic device 202 on surface 206. As mentioned above, the atleast one guiding contour may include a TX antenna element 102. Forexample, a TX antenna element 102 may be included within the mount 802or along the mount's 802 upper surface.

FIG. 8B illustrates the mount contour of a pad 100, when an electronicdevice has been placed on the mount. In some embodiments, the mount 802holds and/or keeps electronic device 202 on the surface 206 of the RFcharging pad 100. Mount 802 is configured to receive the electronicdevice 202 in different configurations. For example, in someembodiments, the electronic device 202 has the one or more movable arms210 folded in different positions and/order (e.g., left arm foldedbefore right arm and vice versa).

FIG. 8B further shows another embodiment of RX antenna element 212. Inparticular, FIG. 8B shows RX antenna element 212 extending the entirelength of the one or more movable arms 210. Additionally, FIG. 8B showsthe surface area of RX antenna element 212 varying as the RX antennaelement 212 moves from wider portions of the one or more movable arms210 to narrower portions.

FIGS. 9A and 9B illustrates another embodiment of the at least oneguiding contour of a surface of the RF charging pad, similar to theembodiment of the pad discussed above that has the guiding contour shownin FIG. 3. In some embodiments, the at least one guiding contour of thesurface 206 is a set of impressions and/or divots 902. In someembodiments, the impressions 902 are configured to receive theelectronic device 202 and position the electronic device 202 over thecenter of the surface 206 of the RF charging pad 100. In someembodiments, the impressions 902 hold the electronic device 202 suchthat the one or more movable arms 210 of the electronic device 202 arein contact with the surface 206 of the housing 204. In some embodiments,the impressions 902 are configured to position electronic device 202 inan optimal position with respect to the two or more TX antenna elements102. In this way, the impressions 902 enable the RF charging pad 100 totransfer energy and/or to improve the efficiency of the energytransferred to the electronic device 202. Additionally, impressions 902provide a visible and/or physical guide for placement of the electronicdevice 202 on surface 206 to reduce the effort needed by the user tocharge the electronic device 202. As mentioned above, the at least oneguiding contour may include a TX antenna element 102. For example, a TXantenna element 102 may be included within the impressions 902 or alongthe impressions' 902 upper surfaces.

FIG. 9B illustrates an embodiment of an impression and/or divot guidingcontour of a surface of the RF charging pad with an electronic deviceplaced in the impressions. FIG. 9B further shows the RX antennaelement(s) 212 placed in and/or at the top of the one or more movablearms 210 (e) (e.g., on the z-axis).

Although FIGS. 6A-9B illustrate different guiding contours andadjustments to the position of electronic device 202 and/or RX antennaelements 212, any placement of the RX antenna element 212 on the RFcharging pad 100 initiates the transmitter controller IC 160 toselectively activate a respective transmitting antenna and/or antennasthat satisfies the matching criteria. In this way, RF charging pad 100is able to transfer energy to charge a battery and/or directly power theelectronic device 202 (via RX antenna elements 212) even if theelectronic device 202 is not properly placed on the RF charging pad. Insome embodiments, one or more of the RF charging pad 100 and the device202 are configured to notify a user if the device 202 has not beenproperly placed on a surface of the pad 100 (e.g., the transmittercontroller IC 160 can be configured to activate a visual alert in theform of one or more LEDs on a surface of the pad 100, the controller IC160 can be configured to send an electronic message to the user, and/orthe controller IC 160 can be configured to provide instructions toproduce an audible alert to a user). In some embodiments, thetransmitter controller IC 160 provides this notification if it isdetermined that the efficiency of energy wirelessly transferred to thedevice 202 falls below a predetermined threshold, such as apredetermined threshold of 40% coupling/transfer efficiency.

Furthermore, in addition to the various guiding contours discussedherein, some embodiments of the pad 100 can also include a visualoutline of the device 202, which can provide another reminder to a useras to how to properly place the device 202 on the pad 100 (e.g., such avisual outline can include dashed lines representing the body and foldedmovable arm portions of the device 202).

FIGS. 10A and 10B illustrate different configurations for the RX antennaelement(s) on and/or in the one or more movable arms of electronicdevice in accordance with some embodiments. As described above, in someembodiments, a RX antenna element 212 is connected to the electronicdevice 202 via one or more movable arms 210. In some embodiments, arespective RX antenna element 212 is located in each movable arm of theone or more movable arms 210. In some embodiments the RX antenna element212 couples to a respective transmitting element of the two or more TXantenna elements (e.g., TX antenna elements 102) to transfer energy fromthe RF charging pad 100 to the electronic device 202. The transferredenergy is used to charge a battery and/or to directly power theelectronic device 202.

As shown in FIG. 10A in some embodiments, a single RX antenna element212 is internally and/or externally connected to electronic device 202via the one or more movable arms 210-1. In some embodiments, the RXantenna element 212 is connected in different positions of the one ormore movable arms 210 (e.g., as described above, RX antenna element 212may be placed on either end of movable arm 210 and/or anywhere inbetween). In some embodiments, the RX antenna element 212 is positionedinternally and/or externally on any side of the one or more movable arms210 (e.g., along the x-axis, y-axis, and/or z-axis). For example, insome embodiments, the RX antenna element 212 is positioned internallyand/or externally on at the left, right, top, and/or bottom of the oneor more movable arms 210. In the embodiment shown in FIG. 10A, the RXantenna element 212 is positioned at the side and at the center of amovable arm 210. In some embodiments, the RX antenna element 212 extendsthe entire length of a movable arm of the one or more movable arms 210.

FIG. 10B illustrates another configuration of RX antenna elements withinone or more movable arms of electronic device. In particular, as shownin the FIG. 10B embodiment, each movable arms 210 includes a respectiveRX antenna element 212 and the respective RX antenna elements 212 areplaced at distinct locations in each movable arm 210. For instance, afirst RX antenna element 1002-1 is located at the top of a first movablearm 1004-1 and a second RX antenna element 1002-2 is located at the sideof a second movable arm 1004-2. As discussed above, the respective RXantenna elements 212 for each movable arm may be the same and/ordistinct.

FIG. 11, a flow chart of a method 1100 of charging an electronic devicethrough radio frequency (RF) power transmission is provided. Initially,a transmitter (e.g., RF charging pad 100) is provided (1102) thatincludes at least two RF transmitting antennas (e.g., TX antennaelements 102, FIGS. 1-4B) for transmitting one or more RF signals orwaves (e.g., an antenna designed to and capable of transmitting RFelectromagnetic waves). In some embodiments, the at least two RF TXantenna elements 102 are arranged symmetrically and/or asymmetrically toone another or in a combination of thereof, thus forming an RF chargingpad 100.

In some embodiments, a receiver (e.g., electronic device 202 includingRX antenna element(s) 212, FIGS. 2, 3 and 5A-5B) is also provided(1104). The receiver includes one or more movable arms 210 that connectthe RX antenna element(s) 212 to the electronic device 202. The RXantenna element(s) 212 are internally or externally included in the oneor more movable arms 210. The RX antenna element(s) 212 are configuredfor receiving RF signals (1114). In some embodiments, the receiver usesthe one or more RF signals to charge a battery and/or to directly powerthe electronic device 202. In use, the receiver is placed (1106) onand/or near the transmitter (e.g., TX antenna elements 102 of RF chargerpad 100, FIGS. 1-4B). For example, the receiver may be placed on top ofat least one RF transmitting antenna (e.g., TX antenna elements 102) oron top of a surface that is adjacent to at least one RF transmittingantenna, such as a surface of a RF charging pad 100.

The transmitter (via the transmitter controller IC 160) detects (1108)the location of the receiver placed on top of the at least one RFtransmitting antenna (e.g., TX antenna elements 102) or on top of asurface that is adjacent to the at least one RF transmitting antenna(e.g., the surface of the charging pad 100). The transmitter (via thetransmitter controller IC 160) selects (1110) a respective RFtransmitting antenna (e.g., TX antenna elements 102) to transmit one ormore RF signals. The respective TX antenna element is selected tooptimize the energy transfer from the transmitter to the receiver (e.g.,via RX antenna element 212). The respective RF transmitting antenna isselected based on matching criteria being satisfied by a detectedreceiver (e.g., RX antenna element 212). For example, as discussedabove, the charging pad 100 (via the transmitter controller IC 160) maydetermine a location of the detected receiver based on the powerreceived by the receiver and use the location to determine therespective RF transmitting antenna. More than one respective RFtransmitting antenna may be selected at a time. In some embodiments, thetransmitter (via the transmitter controller IC 160) selects a respectiveRF transmitting antenna based on information received from the receiver(e.g., RX antenna element 212 and/or electronic device 202). Theinformation is provided to the transmitter via wireless communicationcomponents 110 (e.g., WIFI, BLUETOOTH, and/or other wireless dataconnections). For example, in some embodiments, the transmitter and thereceiver exchange messages via wireless communication, and thesemessages may indicate location information that is used to select therespective RF transmitting antenna.

One or more RF signals are then transmitted (1112) via the selectedrespective RF transmitting antenna(s) and received (1114) by thereceiver (e.g., RX antenna element 212). The system is then monitored(1116/1118) to determine the amount of energy that is transferred viathe one or more RF signals from the selected respective RF transmittingantenna(s) to the electronic device 202 (e.g., via the RX antennaelement 212). In some embodiments, this monitoring (1116) occurs at thetransmitter, while in other embodiments the monitoring (1118) occurs atthe electronic device 202 of the receiver which sends data back to thetransmitter via wireless communication (e.g., WIFI, BLUETOOTH, and/orother wireless data connections). In some embodiments, the transmitterand the receiver exchange messages via wireless communication, and thesemessages may indicate energy transmitted and/or received. The received(1114) one or more RF signals are converted (1120) by the receiver intousable power. The usable power is used to charge a battery and/ordirectly power the receiver.

FIGS. 12A and 12B illustrate the coupling efficiency of the RF chargingpad as measured at a RX antenna element in accordance with someembodiments. In particular, FIGS. 12A and 12B illustrate that thecoupling efficiency is unaffected by the order in which a movable armthat includes a receiving element 212 is folded (e.g., in theirrespective fully folded positions as described above). FIG. 12A shows RFcharging pad 100 the coupling efficiency for a particular electronicdevice 202 configuration overlaid on an x-y axis. In the embodimentshown in FIG. 12A, an electronic device 202 includes one or more movablearms 210 and a movable arm that includes a RX antenna element 212 (e.g.,a single RX antenna element 212 in a movable arm of the one or moremovable arms 210; see FIG. 10A). In FIG. 12A, the movable arm thatincludes the RX antenna element 212 is folded first. In this embodiment,the RX antenna element 212 is at 0 degrees from the center of electronicdevice 202 (e.g., planar). As illustrated in FIG. 12A, the couplingefficiency for the RX antenna element 212 folded first is at least40-50% (e.g. see legend 1202). FIG. 12B illustrates the couplingefficiency of the RF charging pad with the electronic device in andifferent configuration. In particular, FIG. 12B shows, the movable armthat includes the RX antenna element 212 folded second. In thisembodiment, the RX antenna element 212 is at 10 degrees from the centerof electronic device 202 (e.g., 10 degrees from the plane). Asillustrated in FIG. 12B, the coupling efficiency for the RX antennaelement 212 folded second is at least 40-50% (e.g. see legend 1204). Incomparing the coupling efficiency between FIGS. 12A-12B one of ordinaryskill in the art would appreciate that there is minimal (e.g., eitherconfiguration remaining between a coupling efficiency of at least40-50%) to no change in the coupling efficiency based on the order inwhich the one or more movable arms are folded and/or moved.

FIG. 13 illustrates an electromagnetic field as measured at a single RXantenna element in a movable arm that is folded first (e.g., 0 degreesfrom the center or in the fully folded position as described above). Inparticular, FIG. 13 illustrates the transmission of energy to thelocation of the RX antenna element 212. The electromagnetic field isfocused at the location of the RX antenna element 212 while portions ofthe RF charging pad 100 that do not include a RX antenna element 212 arenot activated.

All of these examples are non-limiting and any number of combinationsand multi-layered structures are possible using the example structuresdescribed above.

Further embodiments also include various subsets of the aboveembodiments including embodiments in FIGS. 1-13 combined or otherwisere-arranged in various embodiments, as one of skill in the art willreadily appreciate while reading this disclosure.

The terminology used in the description of the invention herein is forthe purpose of describing particular embodiments only and is notintended to be limiting of the invention. As used in the description ofthe invention and the appended claims, the singular forms “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will also be understood that theterm “and/or” as used herein refers to and encompasses any and allpossible combinations of one or more of the associated listed items. Itwill be further understood that the terms “comprises” and/or“comprising,” when used in this specification, specify the presence ofstated features, steps, operations, elements, and/or components, but donot preclude the presence or addition of one or more other features,steps, operations, elements, components, and/or groups thereof.

It will also be understood that, although the terms “first,” “second,”etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another. For example, a first region couldbe termed a second region, and, similarly, a second region could betermed a first region, without changing the meaning of the description,so long as all occurrences of the “first region” are renamedconsistently and all occurrences of the “second region” are renamedconsistently. The first region and the second region are both regions,but they are not the same region.

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. However, theillustrative discussions above are not intended to be exhaustive or tolimit the invention to the precise forms disclosed. Many modificationsand variations are possible in view of the above teachings. Theembodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, to therebyenable others skilled in the art to best utilize the invention andvarious embodiments with various modifications as are suited to theparticular use contemplated.

1. (canceled)
 2. A charging pad configured to transmit wireless powerwaves for charging an electronic device, the charging pad comprising:two or more transmitting antenna elements that are configured to beselectively activated to transmit wireless power waves to an electronicdevice for wireless charging; and a charging surface including at leastone guiding contour that aligns a position of the electronic device onthe charging surface such that at least one transmitting antenna elementof the two or more transmitting antenna elements is within apredetermined distance of the electronic device and has a predeterminedcoupling efficiency; and a transmitter controller integrated circuit(IC) configured to: detect the position of the electronic device on thecharging surface; and selectively activate at least one transmittingantenna element of the two or more transmitting antenna elements basedon a determination that the at least one transmitting antenna element iswithin the predetermined distance of the electronic device and has thepredetermined coupling efficiency, such that the at least onetransmitting antenna element transmits the wireless power waves to theelectronic device for wireless charging.
 3. The charging pad of claim 2,wherein the predetermined distance from the center of the chargingsurface is less than 5 mm and the predetermined coupling efficiency isat least 42%.
 4. The charging pad of claim 2, wherein the predetermineddistance from the center of the charging surface is less than 2 mm andthe predetermined coupling efficiency is at least 60%.
 5. The chargingpad of claim 2, wherein the predetermined distance from the center ofthe charging surface is less than 0.1 mm and the predetermined couplingefficiency is at least 70%.
 6. The charging pad of claim 2, wherein thetransmitter controller IC is configured to selectively activate anothertransmitting antenna element of the two or more transmitting antennaelements based on a determination that the other transmitting antennaelement is within the predetermined distance of the electronic deviceand has the predetermined coupling efficiency, such that the othertransmitting antenna element transmits the wireless power waves to theelectronic device for wireless charging.
 7. The charging pad of claim 2,wherein the transmitter controller IC is configured to selectivelydeactivate the at least one transmitting antenna element of the two ormore transmitting antenna elements based on a determination that the atleast one transmitting antenna element is not within the predetermineddistance of the electronic device or does not have the predeterminedcoupling efficiency.
 8. The charging pad of claim 2, wherein the atleast one guiding contour is a border that lines at least one edge ofthe charging surface.
 9. The charging pad of claim 2, wherein the atleast one guiding contour is a rise centrally located on the chargingsurface and extending a predetermined height from the charging surface.10. The charging pad of claim 2, wherein the at least one guidingcontour is a mount on the charging surface that is configured to receivethe electronic device and position the electronic device over the centerof the charging surface.
 11. The charging pad of claim 2, wherein the atleast one guiding contour is a set of impressions configured to receivethe electronic device and position the electronic device over the centerof the charging surface.
 12. The charging pad of claim 2, wherein thetwo or more transmitting antenna elements are symmetrically-shapedradiators or asymmetrically-shaped radiators.
 13. The charging pad ofclaim 2, wherein the wireless power waves are radio-frequency powerwaves.
 14. A non-transitory computer-readable storage medium comprisingexecutable instructions that, when executed by one or more processorsthat are coupled with a charging pad that includes two or moretransmitting antenna elements, cause the one or more processors to: atthe charging pad including (i) a charging surface including at least oneguiding contour that aligns a position of an electronic device on thecharging surface such that at least one transmitting antenna element ofthe two or more transmitting antenna elements is within a predetermineddistance of the electronic device and has a predetermined couplingefficiency, and (ii) the two or more transmitting antenna elements,which are configured to be selectively activated to transmit wirelesspower waves to the electronic device for wireless charging: detect theposition of the electronic device on the charging surface; andselectively activate at least one transmitting antenna element of thetwo or more transmitting antenna elements based on a determination thatthe at least one transmitting antenna element is within thepredetermined distance of the electronic device and has thepredetermined coupling efficiency, such that the at least onetransmitting antenna element transmits the wireless power waves to theelectronic device for wireless charging.
 15. The non-transitorycomputer-readable storage medium of claim 14, wherein the predetermineddistance from the center of the charging surface is less than 5 mm andthe predetermined coupling efficiency is at least 42%.
 16. Thenon-transitory computer-readable storage medium of claim 14, wherein thepredetermined distance from the center of the charging surface is lessthan 2 mm and the predetermined coupling efficiency is at least 60%. 17.The non-transitory computer-readable storage medium of claim 14, whereinthe predetermined distance from the center of the charging surface isless than 0.1 mm and the predetermined coupling efficiency is at least70%.
 18. The non-transitory computer-readable storage medium of claim14, wherein the executable instructions that, when executed by one ormore processors, cause the one or more processors to selectivelyactivate another transmitting antenna element of the two or moretransmitting antenna elements based on a determination that the othertransmitting antenna element is within the predetermined distance of theelectronic device and has the predetermined coupling efficiency, suchthat the other transmitting antenna element transmits the wireless powerwaves to the electronic device for wireless charging.
 19. Thenon-transitory computer-readable storage medium of claim 14, wherein theexecutable instructions that, when executed by one or more processors,cause the one or more processors to selectively deactivate the at leastone transmitting antenna element of the two or more transmitting antennaelements based on a determination that the at least one transmittingantenna element is not within the predetermined distance of theelectronic device or does not have the predetermined couplingefficiency.
 20. A method of transmitting wireless power waves forcharging an electronic device, the method comprising: at a charging padincluding (i) a charging surface including at least one guiding contourthat aligns a position of an electronic device on the charging surfacesuch that at least one transmitting antenna element of two or moretransmitting antenna elements is within a predetermined distance of theelectronic device and has a predetermined coupling efficiency, and (ii)two or more transmitting antenna elements that are configured to beselectively activated to transmit wireless power waves to the electronicdevice for wireless charging: detecting the position of the electronicdevice on the charging surface; and selectively activating at least onetransmitting antenna element of the two or more transmitting antennaelements based on a determination that the at least one transmittingantenna element is within the predetermined distance of the electronicdevice and has the predetermined coupling efficiency, such that the atleast one transmitting antenna element transmits the wireless powerwaves to the electronic device for wireless charging.
 21. The method ofclaim 20, wherein the predetermined distance from the center of thecharging surface is less than 5 mm and the predetermined couplingefficiency is at least 42%.